Signaling system



June 21, 1932. F. H; NICHOLSON ET AL 1,854,357

SIGNALING SYSTEM 3 Sheets-Sheet I INVENTORS EZ 'a w bgy w S. (P. a?

ATTORNEY June 21, 1932. F. H. NICHOLSON ET AL 1,864,367

SIGNALING: SYSTEM 3 sheets sheet 2 Filed Feb; 25. 1931 a Z5" I16" I l av1 7 'June 21, 1932.

F. H. NICHOLSON ET AL 1,864,357

SIGNALING SYSTEM Filed Feb. 25, 1931 3 Sh eetS Sheet 5 ATTORNEY LIIPatented June 21, 1932 UNITED STATES PATENT OFFICE FRANK H. NICHOLSONAND HOWARD A. THOMPSON, 'OF EDGEWOOD, PENNSYLVANIA,

ASSIG-NORS TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENN-SYLVANIA, A CORPORATION OF PENNSYLVANIA SIGNALING SYSTEM Applicationfiled February 25, 1931. Serial No. 518,119.

This invention relates to signaling systems and has for an object theprovision of simple and effective means whereby indications may betransmitted from a central point to a shifting vehicle such as alocomotive. The invention also provides an arrangement wherebytranspositions of signal transmitting conductors may be effected foravoiding interference with adjacent telephone lines and radio sets whileat the same time obviating dead-sections at transposition points. Theinvention is particularly well adapted for, though by no means limitedto, cab signaling for freight distributing yards. We shall describe oneform of signaling system embodying our invention and shall then pointout the novel features ther of in claims.

In the accompanying drawings Figure 1 is a diagrammatic view showing oneform 1 of signaling system embodying our invention.

Figures 2 and 3 are vector diagrams indicating certain currentrelationships.

Figured is a diagram illustrating directions of the fluxes setup at agiven instant by the signal transmitting currents in the distributingyard.

Figure 4A is a detail view illustrating one form receiver adapted foruse in systems embodying our invention.

Figure 5 is a diagrammatic view illustrating a transposition arrangementembodying our invention, and

Figures 6, 7 and 8 are vector diagrams illustrating currentrelationships adjacent transposition points.

Referring to Figure 1 of the drawings, the reference character Ydesignates a distributing yard which, as here shown, comprises eightparallel tracks designated 1-8, inclusive, respectively. Trafficnormally enters the yard Y from a main track T and is distributed ontothe yard tracks by a ladder track T Traffic leaves the yard Y on aladder track T and passes over a scale U, which is usually located on ahump, and from which it moves into a classification yard, not shown inthe drawings. In accordance with the usual practice, cars are collectedon the several tracks of the yard Y, and are then pushed over the humpby a shifting locomotive. By

the present invention an operator is enabled to transmit signalindications over a pair of loop circuits to a shifting locomotiveirrespective of the track upon which the locomotive may be operating.

The secondary 10 of a transformer 10 has one terminal connected by wire11 to rai1'12. The latter is connected by wire 18 to railb of track 2,which rail in turn is connected through wire 14: and junction box 14 toa Wire 15. The latter is shown between tracks 4 and 5, and is connectedto the other terminal of transformer secondary 10". One terminal of thesecondary 16 of a transformer 16 is shown connected by a wire 17, torail a of track 7, which rail is connected through wire 18 and junctionbox 14' to conductor 19. The latter extends adjacent wire and isconnected to the other terminal of secondary 16". Wires 15 and 19 arecombined in a two conductor non-ferrous parkway cable placed a shortdistance under the surface of the ballast between tracks 4 and 5. Itwill be seen therefore that the yard is provided with two signalingcircuits. For reasons which will appear hereafter, we prefer to supplythese two circuits with signaling currents which are displaced in phase.

To this end, the primary 10 of transformer 10 is connected to wires 20,21. Wire 20 is connected to one terminal of a generator 22, while wire21 is connected to the other terminal of said generator throughcontroller element 23 and motor-coder controlled contacts as hereinafterdescribed. High frequency current is desirable for the energization ofthe above described signal circuits, for which purpose the generator 22may, for example, supply current of 500 cycles per second. Saidgenerator is driven by motor 2 1 which receives energy from standardcycles mains 25, 26.

The primary 16 of transformer 16 is connected in series with a condenser27 and with the secondary 28" of a transformer 28. The primary 28' ofsaid transformer 28 is connected to wires 20, 21 in parallel withtransformer primary 10.

A motor coder 29 is connected to the mains 25, and 26, and may be of thewell known type comprising an electric motor and a plurality of make andbreak cams driven thereby for causing the opening and closing ofcontacts at different frequencies. In the drawings there are indicatedthree contacts 30, 31 and 32 operable by the motor coder and connectedthrough wire 33 to one terminal of the generator 22. Contact element isoperated by the motor coder to move into and out of engagement withcontact .35, a given number of times per minute; said contact 30engaging contact 35 at the rate, for example, of eighty times perminute. Similarly contact 31 may be operated to engage contact 36 at therate of one hundred and twenty times per minute; while contact 32 may becaused to engage contact 37 one hundred and eighty times per minute.Contacts 35, 36 and 37 are shown connected respectively to selectorcontacts 38, 39,40 engageable by the shiftable controller element 23 inthe cabin of the hump yard operator. Thus, Whenever the element 23 isengaged with any one of contacts 38, 39, 40, the current supplied bygenerator 22 to the transformers 10 and 28, and thence to the respectivecircuits fed by said transformers, is interrupted ata rate dependingupon the rate of operation of the corresponding motor coder contact.When the element 23 is shifted to the position shown, it engages amember 41 which has no connection to the generator 22; and thus in thisposition of said element 23 no current is supplied to the transformersaforesaid.

It will thus be seen that coded energy may be supplied to the circuitsconnected to the respective transformers 10 and 16 (which circuits maybe conveniently referred to as phase A circuit and phase B circuit, re-

1 spectively) and that thereby signals controlled by the element 23 maybe transmitted to the distributing yard. In Figure 3 there is shown avector diagram of the currents flowing in the phase B circuit. Vector 42represents the current lagging behind voltage vector 43 because of therelatively high impedance of the distributor yard circuit. Vector 44represents the voltage drop across condenser unit 27 and vector. 45shows the resultant voltage with current vector 42 leading. Figure 2shows the vector sum of the.

two currents in transformers 10 and 28. Vector 46 represents the currentfed to the primaryof transformer 10, which lags the voltage representedby vector 47, and vector 48 represents the current fed to the primary oftransformer 28, the last mentioned current leading the voltage. Theresultant current, shown by vector 49, is substantially in phase withthe voltage so that approximately unity power factor results. Byproperly choosing and constructing the component parts, an optimum valuecan be given to the phase displacement of the currents in phase A andphase B circuits. We prefer to adjust this displacement to substantially90.

In Figure 4 the relative directions of the fluxes set up at a giveninstant by the currents flowing in rail 6 of track 2, conductor 15, rail(6 of track 7, and conductor 19, are indicated at 50, 51, 52, and 53,respectively. The phase relation of the currents in the circuitsconnected to the transformers 10 and 16 is indicated by arrows A and B,which arrows correspond respectively to said currents. The flux may beutilized in any suitable or convenient'way, as by a receiver mounted onthe train and controlling train carried indication means of well knownform in accordance with the frequency of interruptions in the currentssupplied to phase A and phase B circuits. Any suitable form of receivermay be employed, but we prefer to utilize a receiver in the form shownat K in Figure 4a. The reference character K designates a T-shapedmagnetizable core carried by the train with a vertical leg provided witha winding K With this form of receiver, the vertical components of theflux resulting from currents in the circuits in-the yard link winding Kand induce therein voltages which may, control the train carriedindication meansin the desired manner. As illustrated in Figure 4A, thereceiver is over track 7, and the flux path through the vertical leg andon one side of the head of the core K due to current in the rail a isindicated by the line 52'.

The flux supplied by thecircuits hereinbefore described enables theshifting locomotive to receive the signals from the controllers cabinregardless of the track on which said locomotive is positioned in thedistributor yard. If the locomotive is on either of tracks 1 or 2its'receiving apparatus is influenced almost entirely by the fluxproduced by the current in rail 6 of track 2. If the locomotive is ontrack 3 or track 4, its receiving apparatus is subjected partly to theinfluence of the current in said rail 6 of track 2 and partly to theinfluence of the current in conductors 15 and 19; the fluxes-associatedwith said rail and conductors acting additively on said receivingapparatus when the latter is positioned on track 3 or track 4. Similarlywhen the locomotive is ontrack 5 or 6, the fluxes due to current inconductors 15 and 19 and in rail a of track 7 act additively on thereceiving apparatus. When the locomotive is on either of tracks 7 or 8its receiving apparatus is subject practically entirely to the fluxproduced by the current in rail a of track 7. The signal reproduced inthe locomotive cab. as is well understood, depends upon the frequency ofinterruption of the flux acting upon the receiving coil carried by thelocomotive, and such frequency of interruption depends upon which of thecontacts 30, 31, 32 of the motor coder is in circuit with wire 21. Forexample, when controller element 23 is engaged with contact 39, theindication in the locomotive cab may correspond to slow. When saidelement 2-3 is engaged with contact 38 the cab indication may be fast.When contact 40 is engaged by element 23 the indication may be back up.When no impulses are received, as when element 23 engages contact 41,the corresponding cab ndication is stop.

It is desirable that interference by the signal transmitting currentwith telephone lines and radio sets in the vicinity of the distributingyard be avoided. The avoiding of such interference may be accomplishedby inserting transpositions in the circuits. However, the existence ofdead sections at the transposition points should be obviated sinceotherwise the locomotive would receive a stop" indication at such pointsat all times. We have provided for the effecting of transpositions inthe signal transmitting circuits and at the same time overcoming theeffect of dead sections at the points of transposition. This may beaccomplished by the arrangement shown in Figure 5, which will now bedescribed.

An insulating element is inserted in rail 5 of track 2 and an insulatingelement 56 in rail a of track 7. A wire 57 is connected to said rail 5of track 2 on one side of the in sulating element 55, and is ledadjacent the insulating element 56 in rail a of track 7 said wire beingthence carried to junction box 58 where it is connected to wire 15'. Thelatter is connected by wire 59 to rail 7) of track 2 on the other sideof insulating element 55. A wire 60 connected to said rail on said otherside of insulating element 55 extends to junction box 58 and is thereconnected to a wire 15". Connected to rail (1. of track 7 on one side ofinsulating element 56 is a wire 61 which is connected in junction box 58to a wire 19 which in turn is connected through wire 62 to said rail onthe other side of said insulating element. A wire 63 connected to saidrail a. of track 7 on said other side of element 56 extends adjacent theinsulating element 55 of rail 5 of track 2 .and thence is carried tojunction box 58, wherein it is connected to wire 19". The wires 15, 15",and 19, 19", correspond, of course, to the wires 15, 19, between thetracks 4 and 5 in Figure 1. Thus the wires 15 and 19 may be positionedin a single cable located under the ballast between tracks 4 and 5; andlikewise the wires 15", 19 which are connected respectively to thesecondaries of transformers 10 and 16, may be located in a single cableunder the ballast between said tracks.

It will be seen from the foregoing description that the efi'ect of deadsections associated with transposition points is eliminated by ourarrangement. Thus, the efi'ect of the dead section adjacent insulatingelement 55 in the phase A circuit is obviated by conductor. 63 of thephase B circuit; said conductor 63 transmitting current adjacent saiddead section so that adequate magnetic flux for energizing the receivingapparatus on the locomotive is provided in the region corresponding tosaid dead section. Similarly the conductor 57 of the phase A circuitbridges the region corresponding to the dead section adjacent insulatingelement 56 in the phase B circuit and overcomes the effect of said deadsection. It may be additionally noted that conductor 57 extends adjacentthe dead section region between wire 61 and wire 19 in the terminal box58; while wire 63 extends through the region adjacent the dead sectionbetween wires 15 and 60 in said terminal box. The eflect of these deadsections is thereby eliminated and continuity of signals assured at thetransposition points.

In Figures 6, 7 and 8 the vectors of the currents in the phase A andphase B circuits are indicated in conjunction with the transpositionpoints. The vectors designated A and B correspond respectively to thecurrents in said phase A and phase B circuits; and each set of vectorsin each view represents the current relations in the portion of thecircuit directly thereabove. The arrows in the conductors in these viewsindicate the direction of current flow at a given instant. The sets ofvectors in Figure 6 show the relation of said currents on each side ofand at the transposition points in rail 7) of track 2. Arrow Rrepresents the resultant effect of the currents. Similarly, in Figure 7there are shown vectors indicating the relations between the phase A andphase B currents on each side of and at the transposition points in rail(1 of track 7 while Figure 8 shows the vectors indicating the relationsbetween said currents in the vicinity of the transposition pointsbetween the cables containing conductors 15, 19 and 15", 19". The seriesof vectors in each of said figures shows that the effective currentchanges from one position to another 180 from the first, and that thischange is effected through four intermediate steps in which theresultant vector changes progressively 45 at each stop. It is thusapparent that magnetic flux resulting from said currents is maintainedthroughout the circuits both at transposition points and elsewhere, andthat since there is no point at which the effective current is zero, theshifting locomotive is enabled to receive signals from the controllerirrespective of transposition points.

It should be pointed out that, while we have described our invention asapplied toa cab signal system for use in railroad yards, the inventionis not limited to this use but is equally applicable to the control ofother vehicles such as airplanes, boats, etc.

The terms and expressions which we have features shown and described orportions thereof, but recognize that various modifications are possiblewithin the scope of the invention claimed.

We claim:

1. A vehicle controlling signal system comprising a plurality ofcircuits for inductively transmitting indications to a vehicle,transposed conductors in said circuits, and means providing for thepassage of signal transmitting current across regions corresponding todead sections at transposition points in said circuits.

2. A vehicle controlling signal system, comprising a pair of circuitsfor inductively transmitting indications to a vehicle, transposedconductors in said circuits, and connections from each circuit for thepassage of signal transmitting current across the region correspondingto a dead section at transposition points in the other of said circuits.

3. A vehicle controlling signal system, comprising a plurality ofcircuits for inductively transmitting indications to a vehicle,transposed conductors in one of said circuits, and connections fromanother circuit for the passage of signal transmitting current acrossthe region corresponding to a dead section associated with thetransposition in the first said circuit.

4. A cab signal system for a railway receiving yard, comprising aplurality of trackway circuits for inductively transmitting indicationsto a vehicle on any of a. plurality of tracks, means for supplying tothe 5 respective circuits alternating currents out of phase with eachother, transposed conductors in one of said circuits, and connectionsfrom another of said circuits for the passage of current across theregion corresponding to a dead section associated with the transpositionin the first mentioned circuit.

5. In combination, a plurality of car distributing tracks, means fortransmitting signals to a locomotive on any one of said tracks; saidmeans comprising an alternating current source, a circuit connected tosaid source and comprising a rail of one of said tracks and a conductorpositioned between certain of said tracks, a second circuit comprising arail of one of said tracks, and a conductor adjacent the first mentionedconductor, and means where alternating current out of phase with that inthe first circuit is supplied to the second circuit.

6. In combination, a plurality of car distributing tracks, means fortransmitting signals to a locomotive on any one of said tracks; saidmeans comprising an alternating current source, a circuit connected tosaid source and comprising a conductor positioned between certain ofsaid tracks, a second circuit comprising a conductor adjacent the firstmentioned conductor, and means whereby alternating current out of phasewith that in the first circuit is supplied to the second circuit.

7. In combination, a. plurality of car distributing tracks, a circuitcomprising a conductor positioned between certain of said tracks, asecond circuit comprising a conductor adjacent the first conductor,means for supplying to'said circuits alternating currents out of phasewith each other, transposed conductors in each of said circuits, one ofsaid circuits comprising a conductor arranged adjacent transposedconductors in the other of said circuits for setting up magnetic flux inthe space at transposition points in said other circuit.

8. In'combination a plurality of car distributing tracks, a circuitcomprising a conductor positioned between certain of said tracks, asecond circuit comprising a conductor adjacent the first conductor,means for supplying to said circuits alternating currents out of phasewith each other and means comprising motor coder contacts forinterrupting the currents supplied to said circuits.

9. In a cab signal system for a railway receiving yard, a plurality ofrailway tracks, a circuit comprising a conductor beneath the ballastbetweencertain of said tracks, a second circuit-comprisin a conductorbeneath the ballast between sai tracks, means for supplying to saidcircuits alternating currents out of phase with each other, and meansfor interrupting the currents in said circuits at predetermined rates.

I11 testimony whereof we affix our signatures.

FRANK H. NICHOLSON. HOWARD A. THOMPSON.

